Oskar knofler



UNITED STATES PATENT FFICE.

OSKAR KNUFLER, OF OIIARLOTTENBURG, GERMANY.

GAS-INCANDESCENT.

SPECIFICATION forming part of Letters Patent No. 593,106, dated November2, 1897.

Application filed August 12,1895. $eria1 No. 559,070. (No model.)

To all whont it may concern:

Be it known that I, ()SKAR KNorLnn, of Gharlottenburg, Prussia, Germany,have invented new and useful Improvements in the Manufacture ofGas-Incandescents, of which the following is a full, clear, and exactdescription.

llIy invention relates to the manufacture of gas-incandescents such asare used in the Auer von lVelsbach lamps. These lamps are pro vided withrefractory bodies or mantles adapted to produce light by incandescence,and it is required of these mantles that they should combine a maximumof surface with a minimum of weight. The process which hitherto has beenemployed almost exclusively for the manufacture of such incandescents orrefractory mantles is that described by Auer von I'Velsbach in hisPatents No. 409,531,datedAugust 20,1889,and No. 399,174, dated March 5,1889. According to this usual process porous fibers or threads of acombustible material, such as cotton, 850., being ordinarily in the formof a hose-like tissue, are

impregnated with solutions or emulsions of suitable metallic oxids orsalts, particularly oxids or salts of the so-called metals of the rareearths. The fibers are then dried and burned, the earths remaining as acontinuous body, whose shape is the same as that of the original cottontissue. It has been found in practice that mantles of suflicientstrength will be obtained only when solutions of the abovenam ed saltsare employed. The cotton threads which are employed exclusively inpractice as a temporary support for the salts consist of short fiberstwisted together, and since the texture of the finished mantle closelyresembles that of the cotton support it follows that the said mantleconsists of crossed threads connected to each other merely by beingtwisted together. It will therefore be apparent that considerableimprovement would be effected as to strength and durability of themantles by producing threads having incorporated therewith a substanceor salt which is to be brought to incandescence. This I haveaccomplished in the following manner: It is Well known thatChardonnetrecentlyhas indicated a process whereby threads and textilefabrics may be produced from inorganic cellulosethat is, fromcollodion--whereas previously such threads or fabrics have been madeonly from organic, vegetable, or animal fibers. Ohardonnetproducedartificial silk by forcing a highly-concentrated solution of collodionout of capillary tubes, so as to form threads of the said solution.These threads he allows to pass through water, whereby the alcohol andether are extracted and the thread is fixed. The thread can then bespooled directly without any danger of the threads sticking together.

My improved process for the manufacture of gas-incandescents is somewhatsimilar to the above process. I employ a collodion solution, to which,however, I add the appropriate salts, preferably dissolved in alcohol,these salts, as will be well understood, containing the oxids or saltswhich later on constitute the refractory mantle. Compounds which are notsoluble in alcohol maybe mixed with the collodion in a state of finedivision, thereby forming a kind of emulsion. To this emulsion ormixture of collodion with an inorganic substance maybe added, ifrequired, organic substances, either solid or dissolved such as sugar,camphor, and the like. mixture is forced out of capillary tubes eitherby pressure or by creating a suction at the outlets of the tubes, andthe threads which are produced by this operation are either dried inwarm air or fixed by passing them through water. I may also employ as afixing liquid petroleum-ether, benzol, toluol, sulfureted carbon, or, ingeneral, liquids having the property of extracting or dissolving thealcohol and ether without dissolving the inorganic salts contained inthe threads. In this manner I obtain threads which can be spooled, spun,or woven without further preparation.

It will be obvious that fixing with water is the simplest and cheapestmethod. In order to prevent the solution of the salts from being washedout from the threads, I add to the fixing-water an alkali, preferablyaqua-ammonia, these substances forminga coating of hydrated oxid on thethreads and thereby strengthening them. These threads or textile fabricsmade therefrom are very readily combustible unless organic substances,such as camphor or sugar and the like, have been added thereto, and forthis reason there is The some difficulty in obtaining satisfactorydurable mantles. In order to avoid this, it is necessary to denitratethe threads'prior to combustion. The usual denitrating agents which areemployed in an aqueous solution are not readily available in the presentcase, since the water would also extract a part of the in organic saltsincorporated with the thread. This difficulty may be overcome by addingto the fixing solution (benzin, benzol, &c.) a small quantity offormaldehyde, (hydroxylamin,) sulfureted ammonium, and the like, so thatfixing and denitrating will be accomplished simultaneously. It is,however, preferable to provide for a prolonged action of the denitratingliquid and to leave the threads in the denitrating liquid for theappropriate length of time either in their original condition or afterthey have been spun or woven.

I have found that the best results are obtained The mantles constructedout of such deni trated artificial threads or tissues offer manyadvantages over the usual ones. They are exceedingly strong and durable,and the threads I are more flexible than those used ordinarily,

so that it is easier to give the mantle any shape desired. Anotheradvantage is that they do not contain inorganic substances liable toimpair the power of light emission, as

r in the mantles manufactured according to the \Velsbach method.

I have found that cotton mantles made according to the WVelsbachprocess, even when they are washed with muriatic acid, contain aboutone-half per cent. of ashes before they are impregnated, thesesubstances diminishing the illuminating power of the mantle and,moreover, impairing its stability. The radical difference between myprocess and that of \Velsbach will be apparent. Welsbach employs threadsor fabrics made of natural fibrous materials and impregnates them withthe inorganic refractory substances,whereas I produce artificial threadsfrom a mass which contains the appropriate salts or substancesincorporated therewith. The threads employed or produced by me containno organized matter, and these threads I employ for spinning or weavingthe mantles therefrom.

As an inorganic salt to be added to the collodion I may employ anysoluble or insoluble salt which upon combustion of the threads willleave an oxid 0f sufiicient refractory qualities which will not bevolatile and which will emit a powerful light when incandescent. Themost durable threads are produced by the employment of salts soluble inalcohol, and particularlynitrates, such as nitrate of thorium. I havealso employed the mixture of collodion and an appropriate salt to produce a refractory oxid for the production of mantles in other shapesthan that of threads or tissues. In this case the addition of camphor isof advantage. I have found, however, that these bodies will undergo aconsiderable change of formation by combustion and will not yieldcontinuous mantles of equal quality to those made out of threads.

Having thus described my invention, I claim as new and desire to secureby Letters Patent 1. The process of obtaining threads of collodion forincandescent lighting, consisting in making a nitrocellulose orguncotton solution,adding thereto rare metal earth, and eliminating thesolvent of the solution by an alkaline agent substantially as described.

2. The herein-described method of producing gas-incandescents, whichconsists in fixing the threads by water to which has been added asubstance, preferably an alkali, producing with the salts contained inthe threads, an insoluble compound, and thereby at the same timestrengthening the threads, substantially as described. 7

3. The herein-described method of producing gas-incandescents, whichconsists in mixing a solution containing collodionwith appropriatesubstances to produce incandescent refractory bodies, and then fixingthe product obtained by passing it through a liquid such as benzin,benzol or the like, which is a solvent for alcohol and ether, but willnot dissolve the salts or substances which are to form the refractorymantle, substantially as described.

' 4:. The herein-described method of producing gas-incandescents, whichconsists in mixing a solution containing collodion with appropriatesubstances to produce incandescent refractory bodies, and then fixingthe prod not thus obtained in a liquid consisting of a solvent foralcohol and ether, and a reducing agent for denitrating the product,substantially as described.

5. In a process of manufacturing gasdncandescents from a solutioncontaining collodion mixed with suitable salts adapted to be convertedinto refractory oxids, the herein-described process of denitrating asolid body obtained from the said mixture, which consists in treatingthe said product with an alkalinereducing agent such as sulfuretedammonium, substantially as described.

OSKAR KNoFLER.

Witnesses:

CHARLES H. DAY, GEO. H. WEISS.

IIO

